Amazing Slow Downer (Mac/Win, $39.95) is a standalone application for high-quality, independent manipulation of pitch and playback speed of audio files and CD tracks. Its primary purpose, as its name suggests, is to slow audio playback so you can pick out a musical part and learn it. The author, Rolf Nilsson, is a jazz musician and teacher; his original motivation for Amazing Slow Downer was to provide a practice and transcription aid, but postprocessing save-to-disk options make it a useful DSP tool too. Amazing Slow Downer supports WAV, AIFF, MP3, AAC, and MP4 audio files, and it can convert MP3 files to AIFF format with or without downsampling and bit reduction.
Amazing Slow Downer works with audio CDs and files on your hard drive. Consequently, when you're trying to transcribe a few bars of a song from a CD, you don't need to convert the track to an audio file first. It actually slows down and speeds up CD playback in real time.
Amazing Slow Downer's controls are all on a single screen. On the left side, you select a track or file and view the current playback position in minutes, seconds, and frames (1/75 of a second). At bottom left are controls that enable preprocessing EQ and Karaoke mode (which suppresses material common to both stereo channels), determine whether playback is stereo or mono, and offer a selection of Slow Down algorithms. Loop, speed, and pitch parameter controls are on the right.
You can loop any portion of an audio file or CD track and adjust its pitch in semitones or cents over a two-octave range. Speed can be viewed as Stretch amount (ranging from — 50 to 400 percent) or as a multiple of the original speed (ranging from 20 to 200 percent). A Mix control sets the output's stereo balance, which is handy both for homing in on a single instrument and for adjusting the effect of the Karaoke function. You can save all the aforementioned parameters in up to ten presets for each audio file.
Amazing Slow Downer will import CD tracks and save audio files, with or without processing, to your hard drive. If looping is active, you can choose how many loops to include in the file. The program's import capability is handy for saving clips with altered speed or pitch and for extracting segments of audio CD tracks — for example, from audio sampling CDs.
Whether you do a lot of audio transcription or simply want a convenient utility for pitch and speed change, Amazing Slow Downer is worth a look. You can download a playback-limited demo of Amazing Slow Downer from Roni Music's Web site (www.ronimusic.com).